Process of generating heat.



W. THOMAS I A. E. MAINWARING.

PROCESS 0F GENEHATING HEAT.

APPLICATION FILED SEPT. I7, I9I4. IIENEwED DEC. I4. I9I6. LQIELGS'Y.,

Patontcd Apr. 3, 1917.

3 SHEETS-SHEET 2 NNI IIInIIInWI WIMIIIFMH H H H H IFI I IPL W. THOIVIS & A. E. MAINWARING.

PROCESS 0F GENERATING HEAT.

APPLICATION man 91.11.1914. RENEWED Dic. 14. 1916.

Patented Apr. 3, 1917.

` 3 SHEETS-SHEET 3 Sli WALTER THOMAS lAun ALBERT n. ivrAruwAarNc, or NANAIMO, BRITISH COLUMBIA,

CANADA.

Specification of Letters Patent.

Patented Apr.. 3, tgl?.

original application filed July 9, 1914, Serial' No. 849,924. Divided and this application :filed September 17, 1914, Serial No. 862,238. Renewed December 14, 1916. Serial No. 137,508.

To all whom it may concern.'

Be it known that we, WALTER THOMAS and ALBERT E. MAINWARING, subjects of the King of Great Britain, residing at Nanaimo, in the county of Nanaimo and Province of British Columbia, Canada, have invented certain new and useful improvements in Processes of Generating Heat, of which the following is a specification.

This invention relates to a process of generating heat from low-grade fuel for heating all classes of steam boilers, and for other industrial purposes, such as heating bakery ovens, brick and pottery kilns, ore roasting furnaces, lime and `cement kilns or retorts, etc., in an economical and scientific manner.

At the present time there are large quantities of low-grade fuel, such as mine waste or refuse, lignite, and lignite coal, wood waste and other waste material in 'most parts of the world, which is not successfully utilized for heating purposes, for the reason that the processes and furnaces in general use are not adapted for ,generating high and uniform heat from such classes of fuel.

There are large quantities of cheap, low-y sults above mentioned in a thoroughly pracall tical and scientific manner. By our process we will absolutely do'away with the Smoke nuisance and at the same time eectively utilize the cheap, low-grade fuels, as we have conclusively demonstrated by months of practical operation in our heat generatingF furnace. v

he general object of our invention, therefore, is to generate-high heat under perfect control, from low-grade fuels, by wholly or partially coking the fuel, liberating the rich hydrocarbon gases, completely burning such gases with alr, producing perfect combus- 2 2, Fig. 1.-

tion, also burning the coked fuel and maintaining a regulated temperature at any desired degree.

One of the special objects of-our invention is to provide for coking and gasifying low-grade fuel and producing two` rates of combustion at variable but controlled temperatures,one a comparatively rapid combustion of the gases at a high temperature, and a slower combustion of the fuel at a lower temperature, whereby any desired heat or temperature may be obtained, best suited to the work to be accomplished.

Another object is to provide a process for subjecting Coal or a low-grade fuel to a coking operation, thereby liberating hydrocarbon gases and vapors and injecting the same with air or steam and air, into a body of ignited or incandescent poked fuel, whereby the lrich hydrocarbon vapors are converted into fixed gas, composed principally of hydrogen, light carbureted hydro-gen and carbon monoXid; burning such gases with secondary air in a combustion zona-producing perfect combustion and the highest possible efficiency.

Both the primary and the secondary combustion in our process and generator are under perfect control, so that the exact temperature required maybe obtained. Other objects and purposes of our invention will appear in the detail description of the apparatus and its operation below.

The matter constituting our invention will bedened in the claims.

We will now describe our process by reference to the accompanying drawings, in which- 4 @Figure 1, represents a longitudinal section, with parts in elevation of one form of furnace adapted for carrying out our process, and showing a tubular steam boiler mounted thereon.

Fig. 2, represents a horizontal section through the furnace on the irregular line Fig. 3, represents a sectional detail on 4enlarged scale, showing a lunsen injector on a hollow grate bar.

Fig. 4, represents a detail view of a modified construction of grate bar showing a Bunsen injector.

Fig. 5, represents a sectional view of the air blast injector and gas eXhauster.

Fig. 6, represents a longitudinal section of a modified construction of a boiler 'furnace on line 6 6, Fig. 7.

Fig. 7, represents a transverse section of the same on line 7-7, Fig. 6.

Fig. 8, represents a longitudinal section of a modified arrangement of heat generating furnace.

Fig. 9, represents a transverse section showing modifications.

We construct the walls of our heat generating furnace 1, of brick and may l-ine it with fire brick, and erect on a concrete foundation X, and with an upwardly inclined top 1a, to provide a `heating chamber for the inclinedcoking retort. The furnace 1,

Figs- 1 and 2, is provided with a fueland primary combustion chamber 2, a grate composed of hollow bars 3 land 22 resting on cross bars 4a, and an ash pit 4. The chamber 2, is provided with a front opening and door 5, for clinkering and stoking the bed offuel, and chamber' 4 is provided with an ash door 6. The coking and lfuel feeding retort 7, may be set in an inclined position as shown in Fig. 1, or in a vertical or horii zontal position, and is provided `with a mouth piece 8, having a tight fitting lid or door 9, constructed in any well known manner. The retort is supported in a combustion chamber'lO, so that it may be subjected to a high temperature for coking the coal or other low-grade fuel and liberating rich volatile hydrocarbon gases and vapors. A combustion chamber 10, of comparatively large capacity is provided above the body of fuel on the grate for the secondary and complete combustion of gases.

At one end of the furnace is seated a vertical tubular boiler 12, having a stack 12a, a steam pressure gage 11, a safety valve 11i, and a water gage 11". An outlet `pipe 13, having a valve g, may connect with the combustion chamber 10a, for conducting off hot gaseous products to any desired place of use.

We wish it understood that instead of mounting a steam boiler on our heat generator, a-baking or roasting oven,.or a kiln or other device to be heated may be located at the rear `of the generator or connected there- Awith in any suitable manner for most effectively utilizing the large volume of highly heated products generated.

yA positive air blower 14, of any well known kind, and having an air inlet c, is mounted in any convenient position, and haslan air blast discharge pipe 17 with `which connects a pipe 15, having a valve a,

leading to a secondary air heating coil 1G, located in the top of the boiler or in any flue or conduit for hot gases, whereby it may be heated. The air blast pipe 17, terminates with a nozzle 17, Fig. 5, in the injector 18, to act as an exhauster for drawing gas and vapor from retort 7 through pipe 2O connecting with the mouth-piece 8, as shown. At the outlet of the injector, a pipe 19, is extended to the hollow grate bars 3. Pipe 19, will therefore conduct mixed gas and high pressure air to part of the hollow grate bars, particularly to those marked 3. A second branch pipe 21, having a valve c, connects with pipe 17 and leads to the side hollow grate bars 22, in the furnace.

Any desired number of Bunsen injectors 2 5, will be connected in the grate bars 3, and 22. To form an injector, a nipple 26, Fig. 3, may be screwed into the top of the pipe or bar 3, and is inclosed in an injector bell 27, which is held in place by a spider, or in other desired manner. The construction of grate bar and injector may be modified as shown in Fig. 4, in which is shown a solid grate bar 28, having conical Aopenings 29. A pipe 23, for air blast or mixed air and gas is arranged below bar 28, and is provided with a nipple or nozzle. 24, projecting up into the conical opening 29, for producing a Bunsen burner flame. These Bunsen injectors will draw air or air and water vapor from the ash pit and mix it with the gas or gas and air and force it up into the body of ignited or incandescent fuel. The Bunsen injectors 25, on the air bars 22, will also draw additional air or steam from the ash pit and force it up into the body of fuel, producing a forced draft and rapid combustion, particularly of the rich gases and vapors supplied by pipe 3.

Gas alone may be drawn from the retort 7 and forced into the hollow bars 3 and thence through the injector burners 25 for drawing in air or steam and air and supplying the mixture to the ignited fuel, as indicated by the construction shown in Fig. 9. A hot air pipe 30, having a valve d, connects with the air heating coil 16, at the top of the boiler and with the secondary air ducts 31, in the side walls, which ducts have numerous ports 32, opening into the secondary combustion chamber 10, above the fuel. A branch pipe 35, having a valve c, connects withpipe 19, and leads into the duct 31, or connects by a pipe 36, having avalve h, with air pipe 30, at the rear end of the furnace, so that the mixed gas and air blast can be passed with hot air from pipe 30, into the secondary air ducts 31. We have found it advantageous in some conditions to thus burn all or part of the rich hydrocarbon gas in chamber 10, above the body of fuel. Evidently part of the gas may be burned in the Bunsen injectors at the grate and part in chamber 10, above the solid fuel, according to the character of the gas and other conditions present.

A water supply pipe 33, having a valve f,

connects with the ash pit and supplies it with water to be vaporized. By means of the Bunsen injectors steam is forced into the incandescent fuel where it is decomposed into hydrogen and carbon monoxid, thereby adding to the supply of combustible gasl in the secondary combustion chamber.

The arrangement of coking retorts 7a, shownin Figs. 6 and 7, is particularly adapted for some forms of steam boiler furnaces, and other large furnaces, in which a deep fuel bed is preferably maintained in chamber 2. The retorts 7a may be' supported on shelves or brackets at each side of the furnace and partially surrounded with fiues 10"- for hot products, and are each provided with a bottom opening 7b having a slide 7e for discharge of 'coke into the combustion chamber. The construction of the other parts may be substantially as before described. l

In case a small, inexpensive installation is desired, the coking chamber 7 and fuel chamber 2a, Fig. 8, are made in single inclosing walls and separated by a partition 40, having an opening 41, connecting the chambers, whereby hot coke may be pushed from the coking chamber back into the combustion chamber. One Bunsen burner 25 on an air pipe 22 may'open into the coking chamber for supporting a low or smothered combustion, suitable for coking o r charring the fuel. The chamber'2a will be provided with hollow bars and .injector burners for gas and air 'as above described. Thehot products may be passed off through'a flue.

10d to any desired place of use. lA steamjet eXhauster and air blower 18a may be used kwith this form of heat generator; also with any construction ofour generator, as a substitute for the air blower 14.

The coking retort may have an enlargement 7", to provide 'a gas receiving chamber when the retort is opened forfeeding or discharging fuel. A rotary gas exhauster 18b may be connected in the gas outlet pipe 20, instead of an air or steam jet exhausterl previously described. Air inlet pipes 21a may be placed in, or connected with, theretort or chamber 7 for supplying the'requisite amount of airto hasten the coking operation. Gas drawn by the eXhauster 18b may be forced directly into the hollow bars 3, and thence throughv the injector burners, thereby drawing in air or steam and injecting it into the body of incandescent fuel in chamber 2, where complete combustionis effected and a high heat produced.

The operation of our heat generator is very simple and may be conducted as follows: A body of fuel is placed on the grate and ignited, and the coking retort charged with coal or waste fuel. The air blower may be started and an air blast supplied to.

5 the hollow grate bars. As the temperature hydrogen, light carbureted hydrogen and` carbon monoXid. The volume of gas will be largely increased and the hot gas passing through the body of the fuel will be met by, and intimately mixed with the secondary hot air from the ports 32, resulting in perfect combustion in chambers 10 and 10a, around the coking retort. The so-called smoke will be completely consumed `and the smoke n-uisancethus overcome. The coke will, at suitable intervals, be pushed down into chamber 2, and fresh fuel supplied to the retort in any desired manner. The body of fuel in chamber2, will be regulated and stoked by bars through the door 5. The ashes will be removed as required through door 6. Ashallow body of water will be maintained in the ash pit to supply steam ond, a more rapid combustion of the gases with air, producing a higher temperature.

.Both of 'these rates of combustion will be controlled by controlling the air and gas Aadmitted to the combustion'chambers. Any

desired lheats or temperatures can thus be produced and maintained as may be best suited to the work to be performed.

The high eiciency of our generator is largely effected by the operation of break- Ving up the heavy hydrocarbons, generated in the reto'rt, by the operation of forcing the gases, vapors and air directly into certain areas of the incandescent fuel, as by means of the Bunsen injectors. This we have found much more effective than supplying air under pressure under the whole grate area, which latter we have found absolutely unsuitable for burnin low-grade fuel. By use of a suitable num er of Bunsen-injectors and air under pressure, clinker is formed in cone shaped chunks around and over each injector and can be easlly removed without withdrawing the fire or lowering the temperature of the generator.

-The apparatus herein shown andy described is made the subject of our copending application, Serial Number 849924, filed July 9, 1914.

of incandescent coked fuel, thereby decomposing the mixture into ixed gases, mixing air therewith and producing perfect combustion, whereby lowrade fuel may be used and a high heat o tained.

2. In the generation of heat, the process which consists yin .generating or liberating j hydrocarbon vapors and gases from a body of fuel, drawing off such vapors and gases by a blast of high pressure air, and passing the mixture in jets atlocalized points into a body of incandescentfuel, thereby producing perfect' combustion of the fuel and gases and causing the earthy and mineral matter to be reduced to separate masses of clinker.

3. In the generation of heat, the process which consists in eoking or charring a separate body of fuel and generating hydrocarbon vapors and gases, burning the resulting coke to form a body of incandescent fuel, drawing oii' the hydrocarbon vapors and gases by a. blast of high pressure air from the first body of fuel and forcing them in jets partly above, and partly into, the body of incandescent fuel, thereby producing perfect combustion of the fuel and gases.

4. The process of generating heat which consists in charring or coking a separate body of fuel, and generating hydrocarbon vapors and gases, drawing off and injecting such vapors and gases in separate jets at localized points directly into a body of highly heated or incandescent fuel resultingI from the previous charring or coking operation, and into a combustion chamber above the fuel and supplying air thereto for causing complete combustion, whereby lowgrade fuel may be utilized and perfect combustion produced.

5. In the generation of heat, the process which consists in generating or liberating hydrocarbon vapors and gases from a separate body of fuel, drawing 0H such vapors and gases by a blast of high pressure air, and forcing the mixture in streams into a combustion chamber above the body of incandescent fuel, thereby producing perfect combustion of the fuel and gases.

In testimony whereof we affix our signatures in presence of two witnesses.

WALTER THOMAS. ALBERT E. MAINWARING.

Witnesses:

, M. H. FREEMAN, C. V. FREEMAN. 

